In contrast, complete PDC deficiency (MIM 312170) is associated with lactic acidosis, developmental delay, hypotonia, seizures, polymicrogyria and dysmorphic features32, a phenotype that is more severe than that of CMTX6 likely owing to the tissue specific expression of PDK3 protein, and the presence in many tissues of other kinases that regulate PDC. The gene discussed is PDK3; the disease is lactic acidosis.